The present invention relates to a door locking device that is easily portable and adjustable in length to protect a wide variety of door openings. The door locking device further includes an alarm built integrally with it and having its own power source so that the alarm can be readily installed at the same time and concommitantly with the installation of the door locking device. A problem exists with respect to single door entry units such as hotels and motels in which a number of keys may be available to third parties other than management. Also in a number of cases the doors and the door locks installed by themselves are deficient in providing very little resistance to heavy entry pressure. For example the average door frame may provide only an 1/8" or 1/4" of wood frame resisting inward pushing pressure on the door in its locked condition.
The present invention is adapted to firmly and very strongly resist inward opening pressure on the door. Inward pressure is diverted into a pressure against the floor and it has been found in practice that, before the door can be fully opened with a locking device according to the present invention, it would be necessary to force the door itself off its hinges.
An important feature of the present invention is the incorporation in it of an alarm device which will be operated after limited movement of the door and independently of the locking action. Thus the person who has installed the portable alarm on his door is given an alarm that someone is seeking entry long before the door has been far moved.
The present invention is particularly important since it is adapted to engage existing parts of the door, namely the door handle and to operate directly on the flooring material whether it be carpet, rug or tile.
A number of prior art devices are known which are designed to lock doors against entry. These generally involve complicated arrangements and permanent installations of the locking device with respect to the door and to the floor.
U.S. Pat. No. 1,695,686 issued on Dec. 18, 1928 to S. P. Hess for "Door Secure" shows one such type of door securer. It will be seen that the alarm device is separately mounted and installed in the door and it requires a relatively complicated arrangement and is certainly not portable. The securing device itself requires a declivity in the floor and permanent installation on the inner surface of the door. The present invention overcomes these major disadvantages and provides a single portable unit operable both to secure the door and to give the necessary alarm.
U.S. Pat. No. 2,870,281 issued on Jan. 20, 1959 to F. E. Mitchell for "Burglar Alarm" shows another type of burglar alarm including a locking device with alarm. The alarm however is a telescoping alarm and it requires substantial movement of the door and locking device before there is provided an audible alarm. Also it will be seen that the primary and indeed only operative object of the device is to give an alarm. Ther is not provided the resistance required to aford concommitant locking against the door opening. Also the arrangements shown in this patent is far less portable and adaptable to moving or installation in any available housing unit.
A still further alarm apparatus operable along with a door is shown and described in U.S. Pat. No. 4,139,845 issued on Feb. 13, 1979 to A. F. Washburn. This patent discloses a tip-over type alarm adapted to be in contact with a closed door and to be tipped over by attempted entry. The device is a dual type device being both an alarm and a flashlight. It does not however during its operation as an alarm also give a secure resistance against opening of the door as does the present invention.